About 3% to 6% of the general population is allergic to certain proteins found in latex, which is made from the milk of the rubber tree. Unfortunately, most people don't know whether they are allergic. Patients who've had several previous surgeries and those with food allergies to avocados, bananas and kiwifruit are more likely to be allergic to latex. Healthcare workers are also more likely to be allergic because of their continued exposure to the substance.